Parents are worried about their children playing football, but most haven't decided to keep their kids from putting on a helmet and stepping onto the field.

According to an Associated Press-GfK poll, nearly half of parents said they're not comfortable letting their child play football amid growing uncertainty about the long-term impact of concussions.

In the poll, 44 percent of parents weren't comfortable with their child playing football. The same percentage was uncomfortable with ice hockey, and 45 percent were uncomfortable with participation in wrestling. Only five percent, though, said they have discouraged their child from playing in the last two years as concern over head injuries has increased at all levels of the game.

The majority of parents said they are comfortable with participation in a host of other sports -- including swimming, track and field, basketball, soccer, baseball and softball, among others.

The AP-GfK poll was conducted from July 24-28. It included interviews with 1,044 adults and has a sampling error of plus or minus 3.4 percentage points.

The parents' concern comes as several high-profile lawsuits have challenged how concussions have been addressed in pro and college sports. Thousands of pro players sued the NFL and a $675 million settlement that would compensate them for concussion-related claims is pending. A tentative settlement with the NCAA, meanwhile, would create a $70 million fund to test thousands of current and former college athletes for brain trauma.

Youth and high school programs have increased training available for coaches, and helmet companies are releasing new designs with the hope that they reduce the force of impact. But research is murky about whether or not they will be effective.

Participation statistics also show only a slight decline in the overall number of high school students playing football.

According to the National Federation of State High School Associations, nearly 1.1 million students played 11-man football during the 2012-13 school year. The number was down approximately 10,000 from the year before and more than 20,000 since 2009-08.

Cathy Curtin, a high school rifle coach in northeast Pennsylvania, is one parent who has discouraged her children from playing football in recent years.

Curtin, 52, has gone through concussion-related training for her job, but one issue that concerns her is how much of identifying a head injury relies on the student's input following a collision. She said her 21-year-old son "would have said anything" to remain in the game while in high school, including hiding symptoms such as dizziness from a trainer or coach.

"Our training staff is good, but you can't always know," Curtin said. "You're basing whether they can play on their say. And they are 16-year-old kids, 17-year-old kids who want more than anything to get out there and play."

Curtin said her younger son broke his collarbone and leg while playing football as a freshman.

"Nowhere in that time did they check him for a concussion," Curtin said. "So, if he got hit hard enough to break his collar bone and his leg, then how hard did he hit the ground, too?"

Football wasn't the only sport Curtin said she was uncomfortable with. She also worries about hockey, wrestling and other high-impact competitions such as gymnastics and cheerleading. She's encouraged by new advances -- such as chin straps that change color when a player may have suffered a concussion -- aimed at reducing and identifying head injuries, but she is also skeptical about school districts' ability to afford new helmets.

JeMare Williams, 43, is no stranger to the possibility of getting a concussion while playing football. He thinks he "probably" suffered from one while in high school in St. Louis.

"I don't really know, but I remember being hurt, being dizzy," Williams said. "But during that time, there wasn't a specific diagnosis like now."

Now living in Henderson, Nevada, and with 17- and 11-year-old sons who play the game, Williams -- an auto mechanic -- has the same injury concerns as many parents. That said, he's comfortable with his sons playing football -- or any other sport they choose.

One of the primary reasons for Williams' comfort level is because of the increased attention paid to head injuries over the last few years. He said coaches are trained more closely now to teach proper tackling techniques, as well as watch players for signs of concussions.

"There's a lot of publicity on (concussions) now, and I think that makes it better," Williams said. "So, I'm not as worried now."

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